Self-adaptive control method and device

Abstract

The invention provides a self-adaptive control method and device. The method comprises the steps that multiple pumping flows of a ventricular assist device during operation at a first rotating speed in a first period are obtained; first duration and second duration are recorded, the first duration is the duration of the interval between the adjacent first pumping flow, the second duration is the duration from the first pumping flow to the pumping flow smaller than a first flow threshold value in the first duration, and the first pumping flow is the peak value of the pumping flow of the ventricular assist device; if the first rotating speed is adjusted according to the target ratio, the target ratio is the ratio of the second duration to the first duration. The cardiac cycle of the user and the low flow value of the ventricular assist device can be determined according to the first duration and the second duration respectively, and the rotating speed of the ventricular assist device is adaptively adjusted according to the ratio of the second duration to the first duration, so that the pumping flow of the ventricular assist device can meet the requirements of the user in real time; abnormalities of the ventricular auxiliary device are reduced, and therefore the safety of a user is improved.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to an adaptive control method and device. Background Art

[0002] As an effective means of treating patients with heart failure, the ventricular assist device is an artificial mechanical device that draws fluid from the venous system or the heart directly into the arterial system, partially or completely replacing the work of the ventricles.

[0003] The ventricular assist device is driven by a motor in the housing assembly to rotate the impeller in suspension to pump blood from the left ventricle to the aorta, or from the right ventricle to the pulmonary artery. At present, the speed of the ventricular assist device is generally kept constant at a set speed, but because the user has different requirements for output in different states, the pumping flow of the ventricular assist device may not match the user's current condition. The abnormality caused by this mismatch will damage the patient's heart and aggravate the patient's condition. Summary of the invention

[0004] The embodiments of the present application provide an adaptive control method and device, which can adaptively adjust the rotation speed so that the pumping flow of the ventricular assist device meets the user's medical condition requirements in real time.

[0005] In a first aspect, an embodiment of the present application provides an adaptive control method applied to a ventricular assist device, the method comprising:

[0006] Acquire a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first cycle;

[0007] Recording a first duration and a second duration, wherein the first duration is the duration of intervals between adjacent first pumping flow rates, and the second duration is the duration from the first pumping flow rate to the pumping flow rate less than a first flow rate threshold within the first duration, and the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device;

[0008] The first rotation speed is adjusted according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

[0009] In a second aspect, an embodiment of the present application provides a control device for a ventricular assist device, the control device comprising one or more processors, wherein the one or more processors are used to:

[0010] Acquire a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first cycle;

[0011] Recording a first duration and a second duration, wherein the first duration is the duration of intervals between adjacent first pumping flow rates, and the second duration is the duration from the first pumping flow rate to the pumping flow rate less than a first flow rate threshold within the first duration, and the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device;

[0012] The first rotation speed is adjusted according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

[0013] In a third aspect, an embodiment of the present application provides a ventricular assist device, the ventricular assist device comprising:

[0014] case;

[0015] an impeller disposed in the housing;

[0016] A control unit for controlling the rotation of the impeller, wherein the control unit is used to execute part or all of the steps described in the method described in the first aspect above.

[0017] In a fourth aspect, an embodiment of the present application provides a medical device, comprising a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the program includes instructions for executing some or all of the steps described in the method described in the first aspect above.

[0018] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute some or all of the steps described in the method described in the first aspect above.

[0019] In a sixth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in the method described in the first aspect of the embodiment of the present application. The computer program product may be a software installation package.

[0020] The technical solution provided by the present application obtains multiple pumping flows of the ventricular assist device when it runs at a first speed within a first cycle; records a first duration and a second duration, wherein the first duration is the duration of the interval between adjacent first pumping flows, and the second duration is the duration from the first pumping flow to a pumping flow less than a first flow threshold within the first duration, and the first pumping flow is the peak value of the pumping flow of the ventricular assist device; if the first speed is adjusted according to a target ratio, the target ratio is the ratio of the second duration to the first duration. The present application can determine the user's cardiac cycle and the low flow value of the ventricular assist device according to the first duration and the second duration, respectively, and adaptively adjust the speed of the ventricular assist device by the ratio of the second duration to the first duration, so that the pumping flow of the ventricular assist device can meet the user's needs in real time, reduce abnormalities of the ventricular assist device, and thus improve the safety of the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a schematic structural diagram of a ventricular assist device provided in an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of a ventricular assist device provided by an embodiment of the present application located in a normal position of a patient's heart;

[0024] Figure 3 It is a flowchart of an adaptive control method provided by an embodiment of the present application;

[0025] Figure 4 It is a structural schematic diagram of a medical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to help those skilled in the art better understand the technical solutions of the present application, the following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the description of the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0027] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, software, product, or device that includes a series of steps or units is not limited to the listed steps or units, but also includes steps or units that are not listed, or also includes other steps or units inherent to these processes, methods, products, or devices.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] The medical equipment and pump involved in the present application may be a ventricular assist device (VAD), such as an implantable ventricular assist device, an interventional ventricular assist device, etc.; the ventricular assist device may include at least one blood pump, wherein the blood pump may be a centrifugal pump, an axial flow pump, a magnetic levitation pump, etc.

[0030] "Current" in this application refers to the current driving the motor or motor, which is related to the power of the motor or motor when the supply voltage remains unchanged. "Speed" refers to the rotational speed of the motor or motor, which is related to the rotational speed of the rotor or impeller of the ventricular assist device and can be defined as revolutions per minute. "Flow", "fluid flow", "pumping flow" refers to the volume of fluid delivered by the ventricular assist device per time unit, which can be estimated and measured in liters per minute.

[0031] It should be noted that, in the present application, the term "proximal end" or "proximal side" refers to the end or side closer to the surgical operator; and the term "distal end" or "distal side" refers to the end or side farther from the surgical operator.

[0032] See also Figure 1-Figure 2 , Figure 1 is a schematic structural diagram of a ventricular assist device 100 provided in an embodiment of the present application. Figure 2 1 is a schematic diagram of a ventricular assist device 100 provided in an embodiment of the present application, which is located in a normal position of a user's heart 120. The ventricular assist device 100 can be placed in the user's left heart, right heart, outside the heart, partially outside the heart, partially outside the vascular system, or in any other suitable position in the vascular system. For example, the present application takes the ventricular assist device 100 placed in the left heart as an example for description.

[0033] The ventricular assist device 100 may be percutaneously inserted into the aorta 124 through the femoral artery 122, and pass through the aorta 124 into the left ventricle 128. For example, the ventricular assist device may be percutaneously inserted into the aorta 124 through the axillary artery 123, and pass through the aorta 124 into the left ventricle. In other embodiments, the ventricular assist device 100 may also be directly inserted into the aorta 124, and pass through the aorta 124 into the left ventricle 128. During operation, the ventricular assist device 100 pumps blood in the left ventricle 128 into the aorta 124.

[0034] The ventricular assist device 100 includes a cannula 10. The cannula 10 has a proximal end and a distal end. The distal end of the cannula 10 has a fluid inlet 101, and the proximal end of the cannula 10 has a fluid outlet 102. Blood flows in from the fluid inlet 101 and flows out from the fluid outlet 102 through the cannula 10.

[0035] The ventricular assist device 100 includes an impeller (not shown). The impeller is at least partially located at the proximal end of the cannula 10, such as at the fluid outlet 102 of the cannula 10, so that when the ventricular assist device 100 is in operation, the impeller is driven to rotate to pump blood from the left ventricle 128 to the aorta 124.

[0036] The ventricular assist device 100 may include a motor (not shown in the figure), which may be disposed inside the ventricular assist device 100 or outside the ventricular assist device 100. The present application embodiment takes the case where the motor is disposed inside the ventricular assist device 100 as an example for explanation, for example, the motor is disposed in the motor housing 201, the distal end of the motor housing 201 is connected to the proximal end of the cannula 10, and the motor drives the drive shaft to rotate, thereby driving the impeller to rotate, thereby realizing the blood pumping function of the ventricular assist device 100.

[0037] The ventricular assist device 100 includes a catheter 30, the distal end of which is connected to the proximal end of the motor housing 201, and the drive cable can extend through the catheter 30. For example, the catheter 30 can accommodate an electrical wire connecting the ventricular assist device 100 to an external controller. For example, the ventricular assist device 100 also includes a distal component 110 extending distally from the distal end of the cannula 10, such as a pigtail tube.

[0038] The ventricular assist device 100 also includes a control unit, which can be used to execute any embodiment, aspect and method in the present application. The control unit can be arranged inside the ventricular assist device 100, or it can be arranged outside the ventricular assist device 100. The control unit is used to detect relevant parameters of the ventricular assist device 100 and the user, and to control the operation of the ventricular assist device 100. For example, the control unit supplies current to the motor through one or more wires, and detects the current through a current detection circuit (such as a phase current detection circuit); estimates the current pumping flow rate based on the received current, and controls the rotation speed of the ventricular assist device 100 according to the received instructions; and then detects whether there are abnormal events such as suction and reflux based on the pump speed flow rate and rotation speed, and so on.

[0039] The ventricular assist device 100 is positioned such that the cannula 10 extends across the user's aortic valve 126, the distal end of the cannula 10 is located in the user's left ventricle 128, and the proximal end of the cannula 10 is located in the user's aorta 124.

[0040] In combination with the above description, the present application is described below from the perspective of method examples.

[0041] See also Figure 3 , Figure 3 A schematic diagram of a flow chart of an adaptive control method provided in an embodiment of the present application is applied to Figure 1 and Figure 2 The ventricular assist device shown. Figure 3 As shown, the method includes the following steps.

[0042] S310, obtaining a plurality of pumping flow rates of the ventricular assist device when it operates at a first rotation speed in a first cycle.

[0043] Among them, during the operation of the ventricular assist device 100 in the user's body, the pumping flow through the ventricular assist device 100 depends on the work that the ventricular assist device 100 needs to overcome resistance to pump blood from the left ventricle 128 to the aorta 124. The amount of work done by the ventricular assist device 100 can be quantified as the amount of current that needs to be provided to the motor, that is, the motor current corresponds to the amount of current delivered to the motor of the ventricular assist device 100 when the ventricular assist device 100 is running in the user. During different stages of the cardiac cycle of the user's heart, the load of the motor will change. When the pressure difference in the user's heart changes, the motor current will also change to keep the rotor speed constant. For example, when the flow rate of blood entering the aorta 124 increases (such as during cardiac contraction), the current required by the motor will increase. Therefore, the change in the motor current can help characterize the performance of the heart. That is, during the operation of the ventricular assist device 100, the ventricular assist device 100 has a current-flow characteristic curve, wherein the greater the current, the more work the ventricular assist device 100 does, that is, the greater the pumping flow of the ventricular assist device 100.

[0044] The current of the ventricular assist device 100 can be measured by a phase current detection circuit or any other suitable means (such as a current sensor). The current-flow characteristic curve can be pre-stored in the control unit. Before the ventricular assist device 100 leaves the factory, it can be placed in a test system to test the relationship curve between the pumping flow rate and the current change of the ventricular assist device 100 at different speeds, and then the current-flow characteristic curve is stored in the control unit. The control unit can store the detected current in real time.

[0045] Specifically, when the ventricular assist device 100 is running at the first speed, after the control unit obtains the current curve in the first cycle, it estimates the flow curve corresponding to the current curve using the pre-stored current-flow characteristic curve, and the multiple pumping flows can be pumping flows collected from the flow curve at sampling intervals. The first cycle is greater than the cardiac cycle of a normal person. For example, the first cycle can be m times the cardiac cycle, and m can be 10, 20, 30, etc.

[0046] S320, record a first duration and a second duration, wherein the first duration is the duration of the interval between adjacent first pumping flows, and the second duration is the duration from the first pumping flow to the pumping flow less than the first flow threshold within the first duration, and the first pumping flow is the peak value of the pumping flow of the ventricular assist device.

[0047] In the ventricular systole, the aortic valve 126 or the pulmonary valve opens, and the blood in the ventricle is pumped to the aorta 124 or the pulmonary artery, and the blood volume in the ventricle gradually decreases and the ventricular pressure gradually decreases; in the ventricular diastole, the mitral valve or the tricuspid valve opens, and the blood in the atrium flows to the ventricle, and the blood volume in the ventricle gradually increases and the ventricular pressure gradually increases. Therefore, in the ventricular systole, the blood in the ventricle is pumped to the aorta 124 or the pulmonary artery, and the pumping flow of the ventricular assist device 100 gradually decreases to the minimum value; in the ventricular diastole, the blood in the atrium flows to the ventricle, and the blood volume in the ventricle gradually increases, and the pumping flow of the ventricular assist device 100 gradually increases to the maximum value. That is, the fluctuation of the pumping flow of the ventricular assist device 100 is synchronized with the user's cardiac cycle, so the change of the pumping flow of the ventricular assist device 100 can reflect the current heart state of the user.

[0048] The cardiac cycle of the user can be determined by the adjacent peaks or valleys of the pumping flow of the ventricular assist device 100, that is, the cardiac cycle of the user can be determined by the duration of the interval between the adjacent first pumping flows of the ventricular assist device 100. During the ventricular systole, the pumping flow of the ventricular assist device 100 will reach the lowest. The control unit can determine the duration of the low pumping flow of the ventricular assist device 100 according to the second duration, while the systole and diastole in the user's cardiac cycle are fixed, that is, the change trend and change time of the pumping flow of the ventricular assist device 100 in one cardiac cycle are fixed. When the second duration exceeds the preset duration, it can be considered that the current pumping flow of the ventricular assist device 100 is not synchronized with the user's cardiac cycle. Therefore, the control unit can determine the user's cardiac cycle through the first duration, and then determine whether the current pumping flow of the ventricular assist device 100 is synchronized with the user's cardiac cycle through the second duration, and then synchronize them by adjusting the rotation speed of the ventricular assist device 100 when they are not synchronized.

[0049] S330. Adjust the first speed according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

[0050] In the present application, the ratio of the second duration to the first duration can determine the proportion of low pumping flow in the entire cardiac cycle, and determine whether the ventricular assist device 100 is operating abnormally based on the size of the target ratio, and then resolve the abnormal situation by adjusting the first rotation speed.

[0051] Optionally, adjusting the first speed according to the target ratio includes: if the target ratio is greater than the first target value, increasing the first speed in sequence until the first speed increases by n speed steps, or the difference between the first average flow rate and the second average flow rate is greater than a second flow threshold, the first average flow rate is the average value of the pumping flow rate in the first period, the second average flow rate is the average value of the pumping flow rate in the second period, the first period is earlier than the second period, and n is a positive integer; if the target ratio is less than the second target value, reducing the first speed in sequence until the first speed decreases by n speed steps, or the difference between the second average flow rate and the first average flow rate is greater than the second flow threshold.

[0052] The fluctuation of the pumping flow of the ventricular assist device 100 is synchronized with the cardiac cycle, so the duration of the pumping flow of the ventricular assist device 100 being less than the first flow threshold in one cardiac cycle is within a fixed range. When the target ratio of the second duration to the first duration is greater than the first target value, the ventricular assist device 100 is at a low pumping flow for too long, indicating that the left ventricular pressure of the current user is too low or the aortic pressure is too high, and the low rotation speed of the ventricular assist device 100 may cause reflux problems or insufficient unloading problems, so the control unit can control the increase of the rotation speed of the ventricular assist device 100 to reduce or solve the problems of reflux or insufficient unloading of the ventricular assist device 100. When the target ratio of the second time duration to the first time duration is less than the second target value, the time that the ventricular assist device 100 is at a low pumping flow rate is too short, indicating that the current user's left ventricular pressure is too high or the aortic pressure is too low. The high rotation speed of the ventricular assist device 100 may cause excessive unloading problems or suction problems. Therefore, the control unit may control the rotation speed of the ventricular assist device 100 to reduce or solve the excessive unloading problems or suction problems of the ventricular assist device 100.

[0053] When it is determined according to the target ratio that the current ventricular assist device 100 has regurgitation or insufficient unloading, the control unit can automatically control the rotation speed of the ventricular assist device 100 to increase in sequence. Specifically, the control unit first increases the first rotation speed by the rotation speed step △v, and runs the duration of the first cycle, calculates the target ratio within the cycle, and if the target ratio is still greater than the first target value, continues to increase the rotation speed step △v until the rotation speed step △v is increased n times, or the average value of the pumping flow in the cycle increases by the second flow threshold value compared with the average value of the pumping flow in the previous cycle. That is, when the existence of a regurgitation problem or insufficient unloading is detected, the control unit automatically controls the increase of the rotation speed step △v until the number of increases n is reached, or the ventricular assist device 100 does not have a regurgitation problem or insufficient unloading, or the pumping flow of the ventricular assist device 100 is increased.

[0054] When it is determined according to the target ratio that the current ventricular assist device 100 has excessive unloading or suction, the control unit can automatically control the rotation speed of the ventricular assist device 100 to be reduced in sequence. Specifically, the control unit first reduces the first rotation speed by the rotation speed step △v, and runs the duration of the first cycle, calculates the target ratio within the cycle, and if the target ratio is still less than the second target value, continues to reduce the rotation speed step △v until the rotation speed step △v is reduced n times, or the average value of the pumping flow in the cycle is lower than the average value of the pumping flow in the previous cycle by the second flow threshold. That is, when it is detected that there is an excessive unloading problem or a suction problem, the control unit automatically controls the rotation speed step of reducing △v until the number of increases n is reached, or the ventricular assist device 100 does not have an excessive unloading problem or a suction problem, or the pumping flow of the ventricular assist device 100 is reduced.

[0055] Among them, the first target value and the second target value can be set according to the user's cardiac cycle, such as the first target value is set to 0.23, 0.25, 0.28, etc., and the second target value is set to 0.1, 0.15, 0.18, etc. The first flow threshold is less than the second flow threshold. For example, the first flow threshold is set to 0, and the second flow threshold is set to 1LPM. For example, the first flow threshold is set to 0.3LPM, and the second flow threshold is set to 1LPM. The speed step △v can be determined according to the size of the first speed and the operating speed range allowed by the ventricular assist device 100. The larger the first speed and the closer the first speed is to the nearest boundary value of the operating speed range, the larger the speed step △v. For example, the operating speed range is 23000RPM to 46000RPM. If the first speed is 40000RPM, if it is determined that the first speed is too high and needs to be reduced at this time, the speed step △v can be determined to be 4000RPM. If the first speed is 25000RPM, if it is determined that the first speed is too low and needs to be increased, the speed step △v can be determined to be 4000RPM. If the first speed is 35000RPM, if it is determined that the first speed is too low and needs to be increased, the speed step △v can be determined to be 1000RPM. Where n can be set to 3, 4, 5, 6, etc.

[0056] In the present application, the control unit monitors whether the current ventricular assist device 100 is operating abnormally by the fluctuation of the pumping flow of the ventricular assist device 100, and then when the ventricular assist device 100 is operating abnormally, it immediately and automatically controls to increase the rotation speed of the ventricular assist device 100, promptly reduces or avoids the harm caused by the abnormal operation of the ventricular assist device 100, and improves user safety.

[0057] For example, the method also includes: determining a second pumping flow and a target number, the target number being the number of pumping flows that are less than the first flow threshold in the first time period, and the second pumping flow being the minimum pumping flow in the first time period; if the second pumping flow is less than a third flow threshold and the target number is greater than or equal to the first value, it is determined that reflux exists in the ventricular assist device and an alarm is sounded.

[0058] Blood reflux refers to the phenomenon of blood flowing in the opposite direction of the normal blood flow. For example, the normal blood flow direction is: the blood in the left ventricle 128 flows into the aorta 124. When a large amount of blood in the aorta 124 flows back into the left ventricle 128, it indicates that blood reflux occurs. Blood reflux refers to the blood flowing from the aorta 124 to the left ventricle 128 via the ventricular assist device 100. At this time, the pumping flow of the ventricular assist device 100 is low or even negative. When the pumping flow of the ventricular assist device 100 is not synchronized with the cardiac cycle, such as when the speed of the ventricular assist device 100 is too low and the left ventricular pressure is too high, blood reflux is likely to occur. Reflux can cause complications such as ventricular enlargement and blood loss in the user. If the reflux time is too long, it will seriously endanger the user's health.

[0059] Based on this, the control unit can also monitor in real time whether there is a reflux problem during the operation of the ventricular assist device 100. Specifically: the control unit divides multiple pumping flows into multiple cardiac cycles according to adjacent first pumping flows. Then the number of pumping flows that are less than the first flow threshold in each cardiac cycle and the minimum pumping flow (second pumping flow) in the cardiac cycle are recorded separately. If the second pumping flow is less than the third flow threshold and the target number is greater than or equal to the first value, it is considered that the current ventricular assist device 100 has reflux, and the control unit can alarm and promptly notify medical staff to take solutions as soon as possible. The third flow threshold can be set to 0.5LPM.

[0060] Furthermore, in order to improve the accuracy of monitoring and the sensitivity of alarm, the control unit can continuously monitor the second pumping flow and the target number in the first cycle. If the second pumping flow in the first cycle is continuously less than the third flow threshold and the target number is continuously greater than or equal to the first value, it is confirmed that the current ventricular assist device 100 has reflux and an alarm is issued.

[0061] Among them, when it is confirmed that the ventricular assist device 100 has a reflux phenomenon and an alarm is issued, the control unit can reduce or solve the reflux problem by increasing the rotation speed. Specifically, the first rotation speed is increased by a rotation speed step △v and runs for the duration of the first cycle, and then it is determined whether there is a reflux phenomenon. If the reflux phenomenon still exists, the rotation speed step △v is increased again and the duration of the first cycle is run. This method is followed until there is no reflux phenomenon in the ventricular assist device 100, or the number of times the first rotation speed is increased exceeds n, or the average pumping flow of the ventricular assist device 100 increases by a second flow threshold.

[0062] Furthermore, if during the process of continuously increasing the first rotational speed, the average pumping flow increase of the ventricular assist device 100 exceeds the third flow threshold, the control unit can control the alarm to stop while reducing the current rotational speed of the ventricular assist device 100, and the speed reduction step can be set to the above-mentioned △v.

[0063] In a possible embodiment, the method also includes: obtaining a target characteristic curve, which is a pressure-flow characteristic curve of the ventricular assist device; determining a first pressure differential corresponding to a first average flow at the first speed based on the target characteristic curve, wherein the first average flow is an average value of the multiple pumping flows in the first cycle, and the first pressure differential is the difference between the pressure at the outlet and the pressure at the inlet of the ventricular assist device; if the first pressure differential is less than a first pressure threshold, or the first pressure differential is greater than a second pressure threshold, determining that the blood pressure of a target user is abnormal and sounding an alarm, the target user is a user implanted with the ventricular assist device.

[0064] During the operation of the ventricular assist device 100, the user's ventricular pressure difference may be too low (such as too high left ventricular pressure or too low aortic pressure), or the user's ventricular pressure difference may be too high (such as too low left ventricular pressure or too high aortic pressure). If the user's ventricular pressure is too high or too low, the pumping flow of the ventricular assist device 100 will not match the output demand of the left heart, resulting in problems such as excessive unloading, over-suction, and over-priming of the left ventricle 128.

[0065] Based on this, the control unit can monitor the pressure difference of the left ventricle 128 in real time during the operation of the ventricular assist device 100, detect abnormal blood pressure of the user or abnormalities of the ventricular assist device 100 as early as possible, and issue an alarm to prompt early medical treatment to improve the success rate of treatment.

[0066] The aortic pressure may be too high because the vascular resistance is too large and the blood pressure is high, so that the blood accumulates in the left ventricle 128 and cannot be pumped to the aorta 124. The left ventricular pressure of the user may be too low because the rotation speed of the ventricular assist device 100 is too high, which causes the blood volume in the left ventricle 128 to be too small, or the blood volume in the left ventricle 128 is too small due to systemic hypovolemia or right heart failure. The aortic pressure of the user is too low or the left ventricular pressure is too high because the rotation speed of the ventricular assist device 100 is too low, which causes the blood volume in the left ventricle 128 to be too large.

[0067] In the present application, before the ventricular assist device 100 leaves the factory, the ventricular assist device 100 can be placed in a test environment to measure the characteristic curves of its pumping flow and ventricular pressure difference at different rotation speeds. Then, the pressure flow characteristic curve of each rotation speed is stored in the control unit. When the ventricular assist device 100 is running, the current rotation speed and pumping flow of the ventricular assist device 100 are obtained, and then the current pressure difference of the left ventricle 128 is estimated according to the pressure flow characteristic curve, and whether the current user pressure difference is abnormal is determined according to the size of the ventricular pressure difference.

[0068] Specifically, the control unit can monitor the pumping flow of the ventricular assist device 100 in real time, and calculate the average pumping flow in each first cycle. Then find the first pressure difference corresponding to the current rotation speed from the target characteristic curve. Compare the first pressure difference with the pressure difference between the aortic pressure and the left ventricular pressure when the user is normal. If the first pressure difference is significantly different from the pressure difference when the user is normal, that is, if the first pressure difference is less than the first pressure threshold or greater than the second pressure threshold, it is considered that the current user's blood pressure is abnormal. Abnormal user blood pressure may include: too low left ventricular pressure or too high aortic pressure caused by the ventricular assist device 100 rotating speed being too high, and too high left ventricular pressure or too low aortic pressure caused by the ventricular assist device 100 rotating speed being too low.

[0069] Among them, the first pressure threshold is the difference between the lower limit of the aortic pressure and the upper limit of the left ventricular pressure when the user is normal, and the second pressure threshold is the difference between the upper limit of the aortic pressure and the lower limit of the left ventricular pressure when the user is normal. For example, the first pressure threshold is set to 35mmHg and the second pressure threshold is set to 80mmHg. When the first pressure difference is less than 35mmHg, it is considered that the current user's blood pressure is too low; when the first pressure difference is less than 80mmHg, it is considered that the current user's blood pressure is too high.

[0070] Furthermore, when abnormal blood pressure of the user is detected, the control unit can autonomously adjust the rotation speed of the ventricular assist device 100 to solve the abnormal blood pressure of the user caused by the mismatch between the rotation speed of the ventricular assist device 100 and the current user demand.

[0071] If the first pressure difference is less than the first pressure difference threshold, it indicates that the rotation speed of the ventricular assist device 100 is too low, causing the left ventricular pressure to be too high or the aortic pressure to be too low. At this time, the blood volume in the left ventricle 128 is too large, and the rotation speed of the ventricular assist device 100 needs to be increased; if the first pressure difference is greater than the second pressure difference threshold, it indicates that the current rotation speed of the ventricular assist device 100 is too high, causing the left ventricular pressure to be too low or the aortic pressure to be too high. At this time, the blood volume in the left ventricle 128 is too small, and the rotation speed of the ventricular assist device 100 needs to be increased. Therefore, when it is detected that the first pressure difference is less than the first pressure difference threshold, the control unit controls the rotation speed of the ventricular assist device 100 to increase by the rotation speed step △v in sequence until the first pressure difference is greater than the first pressure difference threshold and less than the second pressure difference threshold, or the number of times the rotation speed step △v is increased exceeds n. Similarly, when it is monitored that the first pressure difference is greater than the second pressure difference threshold, the control unit controls the rotation speed of the ventricular assist device 100 to be reduced by the rotation speed step △v in sequence until the first pressure difference is greater than the first pressure difference threshold and less than the second pressure difference threshold, or the number of times the rotation speed step △v is reduced exceeds n.

[0072] In the embodiment of the present application, the control unit can monitor the user's blood pressure in real time without relying on additional monitoring equipment or devices, and when the user's blood pressure is abnormal, it can reduce or solve the problem of abnormal blood pressure of the user by autonomously adjusting the rotation speed of the ventricular assist device 100, thereby reducing or avoiding the harm caused by abnormal blood pressure and improving user safety.

[0073] In a possible embodiment, after the ventricular assist device is started, the method further includes: obtaining a target efficiency mapping table and a third average flow rate, the target efficiency mapping table being a mapping table between a pressure difference and a rotational speed when the ventricular assist device has the best operating efficiency under the pressure difference, and the third average flow rate being an average pumping flow rate of the ventricular assist device within a third period of time after startup; determining a second pressure difference corresponding to the third average flow rate based on a target characteristic curve; determining a target rotational speed corresponding to the second pressure difference based on the target efficiency mapping table; and adjusting the rotational speed of the ventricular assist device to the target rotational speed.

[0074] In actual applications, the starting speed of the ventricular assist device 100 is set by the doctor based on experience and user conditions. It may take multiple attempts and a long time to find a suitable operating speed. After the operating speed is set, it cannot be adjusted automatically or can only be adjusted according to the set speed adjustment range and adjustment frequency. This may cause the ventricular assist device 100 to operate in a low efficiency zone for a long time, and the advantages of the ventricular assist device 100 cannot be fully utilized. There may be a risk of blood damage or an increased risk of thrombosis.

[0075] Based on this, after the ventricular assist device 100 is started, the control unit can directly adjust the rotation speed of the ventricular assist device 100 to the rotation speed with the best operating efficiency, so as to improve the operating efficiency of the ventricular assist device 100 while reducing the duration of reflux of the ventricular assist device 100 and reducing the harm of reflux to the user.

[0076] Among them, according to the pressure-flow characteristic curve of the ventricular assist device 100, at different speeds, different pumping flows correspond to different ventricular pressure differences. The ventricular pressure difference is the pressure difference between the user's aortic pressure and the left ventricular pressure, and can also be characterized as the pressure difference between the pressure at the outlet and the pressure at the inlet of the ventricular assist device 100. Before the ventricular assist device 100 leaves the factory, it can be placed in a test system to test the pressure-flow characteristic curve of the ventricular assist device 100 at each speed or speed level to mark the pressure difference when the ventricular assist device 100 operates most efficiently at each speed, and then fit the optimal efficiency mapping table of pressure difference and speed.

[0077] After the ventricular assist device 100 is started, the control unit can monitor the pumping flow of the ventricular assist device 100 in real time, and calculate the average pumping flow of the ventricular assist device 100 in the third time period. Then, the second pressure difference corresponding to the current speed is found from the target characteristic curve, and then the speed of the ventricular assist device 100 with the best operating efficiency under the second pressure difference is determined according to the target efficiency mapping table, and then the speed of the ventricular assist device 100 is directly adjusted to the target speed, which can reduce the workload of manual monitoring and adjustment of medical staff, improve efficiency, and always keep the ventricular assist device 100 in the optimal efficiency range.

[0078] The rotation speed at which the ventricular assist device 100 operates with the best efficiency refers to the rotation speed at which the ventricular assist device 100 can provide the same pumping flow or a greater pumping flow with minimal power consumption.

[0079] It should be noted that the target speed can be any value within a speed range. For example, if the target speed is 35000 RPM, when the ventricular assist device 100 is adjusted to a speed within the range of 35000 RPM±1000 RPM, it can be considered that the target speed is reached.

[0080] Further, when the corresponding second pressure difference is less than the low blood pressure alarm threshold or greater than the high blood pressure alarm threshold, that is, when the second pressure difference is less than the first pressure threshold or greater than the second pressure threshold, the control unit may not control the ventricular assist device 100 to adjust to the target speed.

[0081] In a possible embodiment, the method also includes: obtaining a target heart rate, wherein the target heart rate is the number of times the first pumping flow occurs in the ventricular assist device within a preset time; if the target heart rate is less than a first heart rate threshold or greater than a second heart rate threshold, determining that the target user has an abnormal heart rhythm and issuing an alarm.

[0082] In actual applications, in addition to insufficient heart function to pump blood, the user's heart failure also has many complications, such as arrhythmia, ventricular fibrillation, bradycardia or tachycardia and other abnormal heart rhythm problems. Therefore, during the operation of the ventricular assist device 100, the control unit needs to monitor the user's heart rhythm in real time, so that if there is an abnormal heart rhythm, it can alarm in time, prompting the user to seek medical intervention as soon as possible, or prompting the doctor to make a diagnosis as soon as possible and take necessary treatment measures, so as to reduce various risks caused by arrhythmia and improve the user's survival rate.

[0083] The heart rate is the number of times the heart beats in one minute. The length of the cardiac cycle is related to the heart rate, where the heart rate increases and the cardiac cycle shortens. During the operation of the ventricular assist device 100, the control unit monitors the pumping flow of the ventricular assist device 100 in real time, taking the time interval between adjacent first pumping flows as the cardiac cycle, and records the number of times the first pumping flow occurs within 1 minute (i.e., the target heart rate). The target heart rate is then compared with the normal heart rhythm range. If the target heart rate is greater than the first heart rate threshold or the second heart rate threshold, the current heart rhythm is considered abnormal.

[0084] For example, the first heart rate threshold can be set to 40 beats / min, and the second heart rate threshold can be set to 150 beats / min. When the target heart rate is less than 40 beats / min, it is considered that the current target user has bradycardia, and the control unit can alarm to indicate that the user currently has bradycardia. When the target heart rate is less than 150 beats / min, it is considered that the current target user has tachycardia, and the control unit can alarm to indicate that the user currently has tachycardia.

[0085] For example, the control unit can also set the priority of the alarm, set the judgment threshold for bradycardia or tachycardia, and use different alarm levels. For example, when the target heart rate is less than 60 times / min, a low-priority bradycardia prompt can be issued; when the target heart rate is less than 50 times / min, a medium-priority bradycardia alarm can be issued; when the target heart rate is less than 40 times / min, a high-priority bradycardia alarm can be issued.

[0086] Optionally, the method also includes: obtaining a fourth pumping flow within the first time period, the fourth pumping flow being the valley value of the flow pumped by the ventricular assist device; calculating a fourth average flow, the fourth average flow being the average of the fourth pumping flow and the first pumping flow; calculating a target pulsation index based on the first pumping flow, the fourth pumping flow and the fourth average flow; if the target pulsation is less than a pulsation threshold, determining that the target user has an abnormal heart rhythm and sounding an alarm.

[0087] In an embodiment of the present application, the control unit can also monitor the current ventricular fibrillation of the user according to the fluctuation of the pumping flow of the ventricular assist device 100. Specifically, the control unit monitors the pumping flow of the ventricular assist device 100 in real time, records the peak flow Lmax (first pumping flow) pumped by the ventricular assist device 100, and the flow valley Lmin (fourth pumping flow) pumped by the ventricular assist device 100 adjacent to the flow peak, and calculates the average pumping flow Lave (second average flow) between the flow peak Lmax and the flow valley Lmin. Then calculate the fluctuation index of the pumping flow of the ventricular assist device 100, and the fluctuation index PI = (Lmax-Lmin) / Lave. Since the change of the pumping flow of the ventricular assist device 100 is synchronized with the cardiac cycle of the user, the pulsation index of the user can be characterized by the flow fluctuation index of the ventricular assist device 100. If the calculated target pulsation index PI is less than the pulsation threshold, it is determined that the target user currently has ventricular fibrillation, and the control unit can alarm the ventricular fibrillation.

[0088] Furthermore, in order to reduce the risk of false alarms, the control unit can calculate the pulsation index PI in the first cycle. If the pulsation index PI in the first cycle is continuously less than the pulsation threshold, or 80% of the pulsation index PI in the first cycle is less than the pulsation threshold, it is determined that the target user currently has ventricular fibrillation and an alarm is issued.

[0089] Optionally, the method also includes: calculating a target variation coefficient, wherein the target variation coefficient is a ratio of adjacent first pumping flow rates or a ratio of adjacent first time durations; if the target variation coefficient is less than a second value or greater than a third value, determining that the target user has an abnormal heart rhythm and sounding an alarm.

[0090] In the embodiment of the present application, the control unit can also monitor whether the user currently has arrhythmia according to the fluctuation of the pumping flow of the ventricular assist device 100. Specifically, the control unit monitors the pumping flow of the ventricular assist device 100 in the first cycle in real time, records each first pumping flow in the first cycle and the time corresponding to the first pumping flow. Then calculate the coefficient of variation of the pumping flow in the first cycle, that is, calculate the ratio of each adjacent first pumping flow (K i =Lmax i / Lmaxi-1 ), or the ratio of the intervals between adjacent first pumping flows (K i =t i / t i-1 , t i is the time length between adjacent first pumping flow rates), and multiple target variation coefficients are obtained. If multiple target variation coefficients within the first cycle are all less than the second value or greater than the third value, it is determined that the current target user has an arrhythmia, and the control unit can detect the arrhythmia and issue an alarm.

[0091] The first value and the second value may be set according to the normal heart rhythm of the target user. For example, the second value may be set to 0.8 and the first value may be set to 1.2.

[0092] In the embodiment of the present application, the control unit can calculate the abnormal flow fluctuation phenomenon according to the characteristic that the pump flow change of the ventricular assist device 100 is consistent with the cardiac cycle. Without any other additional monitoring equipment or devices, it can continuously monitor the patient's heart rhythm in real time, and determine the corresponding abnormal heart rhythm situation (such as tachycardia, ventricular fibrillation, premature beats, etc.) and issue an alarm, prompting the user to seek medical intervention as soon as possible, or prompting the doctor to make a diagnosis as soon as possible and take necessary treatment measures to reduce the various risks brought by arrhythmia and improve the user's survival rate.

[0093] It can be seen that the present application proposes an adaptive control method, which obtains multiple pumping flows of the ventricular assist device when it runs at a first speed within a first cycle; records a first duration and a second duration, wherein the first duration is the duration of the interval between adjacent first pumping flows, and the second duration is the duration from the first pumping flow to a pumping flow less than the first flow threshold within the first duration, and the first pumping flow is the peak value of the pumping flow of the ventricular assist device; if the first speed is adjusted according to a target ratio, the target ratio is the ratio of the second duration to the first duration. The present application can determine the user's cardiac cycle and the low flow value of the ventricular assist device according to the first duration and the second duration, respectively, and adaptively adjust the speed of the ventricular assist device by the ratio of the second duration to the first duration, so that the pumping flow of the ventricular assist device can meet the user's needs in real time, reduce abnormalities of the ventricular assist device, and thus improve the safety of the user.

[0094] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the execution process on the method side. It is understandable that in order to realize the above functions, the network device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiment provided in this article, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0095] For example, the present application provides a control device for a ventricular assist device, the control device comprising one or more processors, the one or more processors being used to: obtain multiple pumping flows of the ventricular assist device when it operates at a first speed within a first cycle; the first time duration is the time duration of intervals between adjacent first pumping flows, the second time duration is the time duration from the first pumping flow to the pumping flow less than a first flow threshold within the first time duration, the first pumping flow being the peak value of the pumping flow of the ventricular assist device; and adjust the first speed according to a target ratio, the target ratio being the ratio of the second time duration to the first time duration.

[0096] For example, the present application also provides a ventricular assist device, characterized in that the ventricular assist device comprises:

[0097] case;

[0098] an impeller disposed in the housing;

[0099] A control unit for controlling the rotation of the impeller, wherein the control unit is used for part or all of the steps described in the above method.

[0100] As an example, the present application also provides a medical device, which includes the control device or ventricular assist device described above.

[0101] Among them, the control device of each of the above schemes has the function of implementing the corresponding steps performed by the medical equipment in the above method; the functions can be implemented by hardware, or by hardware executing corresponding software.

[0102] In the embodiments of the present application, the control device may also be a chip or a chip system, such as a system on chip (SoC).

[0103] See also Figure 4 , Figure 4It is a structural diagram of a medical device provided in an embodiment of the present application, wherein the medical device comprises: one or more processors, one or more memories, one or more communication interfaces, and one or more programs; the one or more programs are stored in the memories and are configured to be executed by the one or more processors.

[0104] The above program includes instructions for performing the following steps:

[0105] Acquire a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first cycle;

[0106] The first duration is the duration of the interval between adjacent first pumping flow rates, the second duration is the duration from the first pumping flow rate to the pumping flow rate less than the first flow rate threshold within the first duration, and the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device;

[0107] The first rotation speed is adjusted according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

[0108] Among them, all relevant contents of each scenario involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0109] It should be understood that the above-mentioned memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0110] In the embodiment of the present application, the processor of the above-mentioned device may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0111] It should be understood that the "at least one" involved in the embodiments of the present application refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0112] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first information and the second information are only used to distinguish different information, and do not indicate the difference in content, priority, sending order or importance of the two types of information.

[0113] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software units in a processor for execution. The software unit can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0114] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program enables a computer to execute part or all of the steps of any method recorded in the above method embodiments.

[0115] The present application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps of any method described in the above method embodiment. The computer program product may be a software installation package.

[0116] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0117] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0118] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0119] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0120] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0121] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, server or TRP, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0122] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing the relevant hardware through a program, and the program may be stored in a computer-readable memory, which may include a flash drive, ROM, RAM, a magnetic disk or an optical disk, etc.

[0123] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An adaptive control method, characterized in that: Applied to a ventricular assist device, the method comprises: Acquire a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first cycle; Recording a first duration and a second duration, wherein the first duration is the duration of intervals between adjacent first pumping flow rates, and the second duration is the duration from the first pumping flow rate to the pumping flow rate less than a first flow rate threshold within the first duration, and the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device; The first rotation speed is adjusted according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

2. The method according to claim 1, characterized in that The adjusting the first speed according to the target ratio comprises: If the target ratio is greater than the first target value, the first speed is increased sequentially until the first speed increases by n speed steps or the difference between the first average flow rate and the second average flow rate is greater than a second flow rate threshold, the first average flow rate is the average value of the pumping flow rate in the first period, the second average flow rate is the average value of the pumping flow rate in the second period, the first period is earlier than the second period, and n is a positive integer; If the target ratio is less than the second target value, the first speed is reduced in sequence until the first speed is reduced by the n speed steps or the difference between the second average flow and the first average flow is greater than the second flow threshold.

3. The method according to claim 1, characterized in that The method further comprises: Determine a second pumping flow rate and a target number, wherein the target number is the number of pumping flows less than the first flow threshold value during the first time period, and the second pumping flow rate is the minimum pumping flow rate during the first time period; If the second pumping flow rate is less than a third flow threshold, and the target number is greater than or equal to a first value, it is determined that reflux exists in the ventricular assist device and an alarm is sounded.

4. The method according to claim 1, characterized in that: The method further comprises: Acquiring a target characteristic curve, wherein the target characteristic curve is a pressure-flow characteristic curve of the ventricular assist device; Determine, according to the target characteristic curve, a first pressure difference corresponding to a first average flow rate at the first speed, wherein the first pressure difference is a difference between a pressure at an outlet and a pressure at an inlet of the ventricular assist device; If the first pressure difference is less than a first pressure threshold, or the first pressure difference is greater than a second pressure threshold, it is determined that the blood pressure of the target user is abnormal and an alarm is issued, and the target user is a user implanted with the ventricular assist device.

5. The method according to claim 1, characterized in that After the ventricular assist device is activated, the method further comprises: Acquire a target efficiency mapping table and a third average flow rate, wherein the target efficiency mapping table is a mapping table between a pressure difference and a rotation speed when the ventricular assist device has the best operating efficiency under the pressure difference, and the third average flow rate is an average pumping flow rate of the ventricular assist device within a third period of time after startup; Determining a second pressure difference corresponding to the third average flow rate according to the target characteristic curve; determining a target speed corresponding to the second pressure difference according to the target efficiency mapping table; The rotation speed of the ventricular assist device is adjusted to the target rotation speed.

6. The method according to claim 1, characterized in that The method further comprises: Acquire a target heart rate, where the target heart rate is the number of times the first pumping flow rate of the ventricular assist device occurs within a preset time; If the target heart rate is less than the first heart rate threshold or greater than the second heart rate threshold, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

7. The method according to claim 1, characterized in that The method further comprises: Acquire a fourth pumping flow rate within the first time period, wherein the fourth pumping flow rate is a flow valley value of the ventricular assist device pumping; Calculating a fourth average flow rate, where the fourth average flow rate is an average value of the fourth pumping flow rate and the first pumping flow rate; calculating a target pulsatility index according to the first pumping flow rate, the fourth pumping flow rate, and the fourth average flow rate; If the target pulsation is less than the pulsation threshold, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

8. The method according to claim 1, characterized in that The method further comprises: Calculating a target variation coefficient, wherein the target variation coefficient is a ratio of adjacent first pumping flow rates or a ratio of adjacent first time durations; If the target variation coefficient is less than the second value or greater than the third value, it is determined that the target user has an abnormal heart rhythm and an alarm is issued.

9. A control device for a ventricular assist device, characterized in that: The control device comprises one or more processors, wherein the one or more processors are configured to: Acquire a plurality of pumping flow rates of the ventricular assist device when the ventricular assist device operates at a first rotation speed in a first cycle; Recording a first duration and a second duration, wherein the first duration is the duration of intervals between adjacent first pumping flow rates, and the second duration is the duration from the first pumping flow rate to the pumping flow rate less than a first flow rate threshold within the first duration, and the first pumping flow rate is the peak value of the pumping flow rate of the ventricular assist device; The first rotation speed is adjusted according to a target ratio, where the target ratio is a ratio of the second duration to the first duration.

10. A ventricular assist device, characterized in that: The ventricular assist device comprises: case; an impeller disposed in the housing; A control unit for controlling the rotation of the impeller, wherein the control unit is used to execute the steps in the method according to any one of claims 1 to 8.

11. A medical device, characterized in that: The method comprises a processor, a memory and a communication interface, wherein the memory stores one or more programs, and the one or more programs are executed by the processor, and the one or more programs include instructions for executing the steps in the method according to any one of claims 1 to 8.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute the steps of the method according to any one of claims 1 to 8.

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